Luminaires



Nov. 16, 1965 MULLER ETAL LUMINAIRES Filed Aug. 20, 1963 Josef M'u'lller United States Patent 3,218,451 LUIVHNAIRES Josef Miilier and Karl Liiwenstein, Neheim-Husten, Germany, assignors to Trilux-Lenze K.G., Neheim-Husten, Germany, a firm of Germany Filed Aug. 20, 1963, Ser. No. 304,299 Claims priority, application Germany, Apr. 30, 1963, T 23,922 3 Claims. (Cl. 24i)128) This application is a continuation-in-part of our copending patent application Serial No. 212,778, filed July 27, 1962, now Patent No. 3,164,327 for luminaires.

This invention has reference to luminaires for fluorescent lamps, and more particularly to composite luminaires comprising an upper supporting frame structure open at the lower side thereof, and further comprising a light-diffusing trough for closing said open lower side of said frame structure.

Luminaires of the above description call for simple, rugged and easy to handle means for securing the lightdiifusing trough to the frame structure.

It is, therefore, one object of this invention to provide improved luminaires which fully comply with these requirements.

Another object of this invention is to provide luminaires of the above description including improved snapon fastener means for attaching the light-diffusing trough to the frame structure above it.

Still another object of the invention is to provide luminaires of the above description having snap-on fastener means which lead themselves particularly well to be associated with light-diffusing troughs made of a plastic material such as, for instance, a synthetic-resin-fiber-glass laminate.

A further object of the invention is to provide luminaires of the above description wherein the light-diffusing troughs may be made of a relatively thin material having a relatively small dimensional stability and tending to be easily deformed with snap-on fastener means tending to preclude deformation of the light-diffusing troughs when in position and to establish tight joints between the frame structures of the luminaires and the light-diffusing troughs thereof.

Still another object of the invention is to provide luminaires for fluorescent lamps having improved snap-on fastener means for joining the light-diffusing trough to the frame structure, which fastener means are internal, not apparent from the outside of the luminaire and do not increase the bulk of the latter.

The foregoing and other objects of the invention and advantages thereof will more clearly appear from the ensuing particular description of the invention, as illustrated in the accompanying drawing wherein:

FIG. 1 is in part a side elevation and in part a vertical section of an embodiment of the invention showing the light-diffusing trough in the position it has when firmly attached to the frame srtucture of the luminaire;

FIG. 2 is a bottom plan view of the structure of FIG. 1;

FIG. 3 is in part a side elevation and in part a vertical section of the structure of FIG. 1, the light diffusing trough being shown in the position it has immediately before being attached to the frame structure of the luminaire, or immediately following removal from that structure.

Referring now to the drawings, numeral 1 has been applied to indicate the upper supporting frame structure of a luminaire open at the lower side thereof. The upper side of frame structure 1 is intended to be suspended from a ceiling (not shown). The fluorescent lamps and their auxiliary equipment, such as the ballast chokes, the starting switches, etc. (not shown in any of the figures) are intended to be affixed to, and supported by, frame structure 1. Light-difiusing trough 2 of which but a portion is shown in the drawing closes the open lower side of frame structure 1. Trough 2 is preferably made of a synthetic-resin-glass-cloth laminate, or glass fiber reinforced plastic. Both sides of frame structure 1 are provided with horizontally outwardly projecting flanges 3, FIGS. 1 and 3 showing but one of these flanges situated on one side of frame structure 1. All the parts of the luminaire of FIGS. 1 and 3 are symmetrical with regard to a vertical longitudinal plane of symmetry and, therefore, it is suflicient for a full understanding of that luminaire to illustrate but the portion thereof situated to one side of the aforementioned vertical median plane or plane of symmetry. The horizontal flanges 3 are followed by outwardly downwardly flaring surfaces 4, vertical surfaces 4a and horizontal edge portions 5 which are bent inwardly, i.e. toward the aforementioned vertical plane of symmetry. Surface 3 is provided with a gasket 6 in strip-form extending along the entire side of the luminaire. Strip 6 is preferably made of foam rubber.

Trough 2 comprises an inwardly slanting lateral edge portion 20 at the side thereof adjacent frame structure 1 adapted to engage surface 3, or gasket strip 6, respectively, by which surface 3 is covered.

The structure shown in the drawings further comprises means for clamping the trough 2 against the frame structure of the luminaires which means will be described below more in detail.

As shown in FIGS. 1-3 there are U-shaped bracket means within the frame structure of the luminaire integral with said frame structure including vertical flange portions 33 of which each defines a substantially horizontal slot 34. Slots 34 are open at the end thereof next to the vertical median plane or plane of symmetry of the frame structure and closed at the other end thereof. The horizontal web portion of the aforementioned bracket means is aflixed to a horizontal wall portion 3 of the frame structure and has an extension 36 bent degrees out of the plane defined by the aforementioned web portion. Extension 36 is a spring abutment as will be more apparent from what follows and is provided with a rectangular slot or aperture 37. The luminaire of FIGS. l-3 further comprises a substantially T-shaped supporting element 32 including a pair of flange portions 31 having ends inserted into the slots 34 in flange portions 33 of the aforementioned U-shaped bracket means and slidably guided within said slots. Supporting element 32 further includes a web portion 32a having an end inserted into, and slidably arranged within, slot 37 of spring abutment surface 36. A helical spring 25 is mounted on the web portion 32a of T-shaped supporting element 32 resting with one end thereof against spring abutment surface 36 and resting with the other end thereof against the flange portions 31 of supporting element 32. Thus spring 35 biases flange portions 31 from right to left, as seen in FIGS. 1-3. The flange portions 31 of supporting element 32 includes a bend 40 and an extension 41 flaring inwardly toward the aforementioned median plane of the luminaire. Extension 41 is adapted to be cooperatively engaged by the inwardly slanting edge portion 20 of trough 2 when the latter is being inserted into the frame structure of the luminaire as clearly shown in FIG. 3. The lateral edges 50 of extension 41 converge toward the lowest point thereof as is apparent from FIG. 2.

Reference character 42 has been applied to indicate a vertical abutment or guide surface for trough 2. Surface 42 may be formed by a bent portion of the aforementioned U-shaped bracket, i.e., a portion bent 90 degrees in the same fashion as spring abutment surface 36. As an alternative, surface 4-2 may be formed by a bent downward flap or extension of the horizontal surface 3 of the frame structure.

Upon insertion of the inwardly slanting lateral edge portion 20 of the light-diffusing trough into the gap formed between surface 42 and extension 41 edge portion 20 engages extension 41 and moves supporting element 32 against the bias of spring 35 from left to right as seen in FIGS. 1-3. At a given level of trough 2 supporting element 32 reaches its right limit position. When trough 2 is further raised supporting element 32 reverses the direction of its movement, i.e. it moves from right to left, as seen in FIGS. 1-3, ultimately reaching its left limit position shown in FIG. 1. In that position the bent extension 41 of supporting element clamps the lateral side of luminaire 2 against abutment surface 42 and the upper edge of luminaire 2 against gasket 6.

It will be understood that we have illustrated and described herein a preferred embodiment of the invention and that various alterations may be made in the details thereof without departing from the spirit and scope of the invention as defined in the appended claims.

We claim as our invention:

1. A luminaire for fluorescent lamps comprising in combination:

(a) an upper supporting frame structure having a longitudinal median plane;

(b) a light-diffusing trough arranged at the lower side of said frame structure, said trough including an inwardly slanting lateral edge portion at the side thereof adjacent said frame structure;

(c) an abutment surface integral with said frame structure adapted to be engaged by a portion of said trough;

(d) a bracket integral with said frame structure defining a pair of spaced parallel substantially horizontal slots open at one end thereof and closed at the other end thereof, said bracket including a spring abutment surface arranged at right angles to the planes within which said pair of slots are situated and defining an additional slot therein;

(e) a substantially T-shaped supporting element including a pair of flange portions having ends inserted into and slidably arranged within said pair of slots, said supporting element further including a web portion inserted into and slidably arranged in said additional slot;

(f) a helical spring mounted on said web portion of said supporting element resting with one end thereof against said spring abutment surface and resting with the other end thereof against said pair of flange portions of said supporting element; and

(g) a trough guiding and clamping means formed by an extension of said pair of flange portions of said supporting element bent in downward direction inwardly toward said longitudinal median plane of said frame structure.

2. A luminaire as specified in claim 1 wherein said extension has a pair of edges converging toward the lowest point of said extension.

3. A luminaire for fluorescent lamps comprising in connection:

(a) an upper supporting frame structure having a longitudinal median plane;

(b) a light-diffusing trough arranged at the lower side of said frame structure, said trough including an inwardly slanting lateral edge portion at the side thereof adjacent said frame structure;

(c) a bracket integral with said frame structure defining a pair of spaced parallel substantially horizontal slots open at one end thereof and closed at the other end thereof, said bracket including a spring abutment surface arranged at right angles to the planes within which said pair of slots are situated and defining an additional slot therein, and said bracket further comprising a trough abutment surface arranged substantially parallel to said spring abutment surface and adapted to be engaged by a portion of said trough;

(d) a substantially T-shaped supporting element including a pair of flange portions having ends inserted into and slidably arranged within said pair of slots, said supporting element further including a web portion inserted into and slidably arranged in said additional slot;

(e) a helical spring mounted on said web portion of said supporting element resting with one end thereof against said spring abutment surface and resting with the other end thereof against said pair of flange portions of said supporting element; and

(f) a trough guiding and clamping means formed by an extension of said pair of flange portions of said supporting element bent in downward direction inwardly toward said longitudinal median plane of said frame structure.

References Cited by the Examiner UNIT ED STATES PATENTS NORTON ANSHER, Primary Examiner. 

1. A LUMINAIRE FOR FLUORESCENT LAMPS COMPRISING IN COMBINATION: (A) AN UPPER SUPPORTING FRAME STRUCTURE HAVING A LONGITUDINAL MEDIAN PLANE; (B) A LIGHT-DIFFUSING TROUGH ARRANGED AT THE LOWER SIDE OF SAID FRAME STRUCTURE, SAID TROUGH INCLUDING AN INWARDLY SLANTING LATERAL EDGE PORTION AT THE SIDE THEREOF ADJACENT SAID FRAME STRUCTURE; (C) AN ABUTMENT SURFACE INTEGRAL WITH SAID FRAME STRUCTURE ADAPTED TO BE ENGAGED BY A PORTION OF SAID TROUGH; (D) A BRACKET INTEGRAL WITH SAID FRAME STRUCTURE DEFINING A PAIR OF SPACED PARALLEL SUBSTANTIALLY HORIZONTAL SLOTS OPEN AT ONE END THEREOF AND CLOSED AT THE OTHER END THEREOF, SAID BRACKET INCLUDING A SPRING ABUTMENT SURFACE ARRANGED AT RIGHT ANGLES TO THE PLANES WITHIN WHICH SAID PAIR OF SLOTS ARE SITUATED AND DEFINING AN ADDITIONAL SLOT THEREIN; (E) A SUBSTANTIALLY T-SHAPED SUPPORTING ELEMENT INCLUDING A PAIR OF FLANGE PORTIONS HAVING ENDS INSERTED INTO AND SLIDABLY ARRANGED WITHIN SAID APIR OF SLOTS, SAID SUPPORTING ELEMENT FURTHER INCLUDING A WEB PORTION INSERTED INTO AND SLIDABLY ARRANGED IN SAID ADDITIONAL SLOT; (F) A HELICAL SPRING MOUNTED ON SAID WEB PORTION OF SAID SUPPORTING ELEMENT RESTING WITH ONE END THEREOF AGAINST SAID SPRING ABUTMENT SURFACE AND RESTING WITH THE OTHER END THEREOF AGAINST SAID PAIR OF FLANGE PORTIONS OF SAID SUPPORTING ELEMENT; AND (G) A TROUGH GUIDING AND CLAMPING MEANS FORMED BY AN EXTENSION OF SAID PAIR OF FLANGE PORTIONS OF SAID SUPPORTING ELEMENT BENT IN DOWNWARD DIRECTION INWARDLY TOWARD SAID LONGITUDINAL MEDIAN PLANE OF SAID FRAME STRUCTURE. 